I use RG-58 for all my HF antennas, since it's light, flexible, convenient, and cheap. And super easy to choke. Whenever I have a problem I just loop a few turns of it on a ferrite core and the problem goes away. Since I operate 100W max and all my antennas are properly matched, I don't think power loss is a concern.
But in a recent discussion I was told by a ham that he "doesn't bother with anything less than RG213". I looked up the specs for the cable I'm using and the loss is 10.5dB every 100m at 50MHz. My interconnects are 10-12m max and for now I only operate 40 and 20m.
I don't see a reason to upgrade my RG58 to something better (LMR400 is what I would go with), but maybe I'm missing something?
I do see a benefit in going with lower loss for VHF and especially UHF and up. But is there a reason, other than pushing kilowatts, to go with lower loss cable?